malaria

noun

1. (countable, uncountable)A disease spread by mosquito, in which a protozoan, Plasmodium, multiplies in blood every few days.
2. (archaic, countable, uncountable)Supposed poisonous air arising from marshy districts, once thought to cause fever.

   “The doctor had his hands full, as the air was so impregnated with malaria that men who had only landed some twenty-four hours were laid low with this extraordinarily violent type of fever.”